Apparatus for continuous extrusion of composite bodies of plastic material



J n 1965 F. REIFENHAUSER 3,189,941

1 APPARATUS FOR CONTINUOUS EXTRUSIQN OF COMPOSITE BODIES OF PLASTICMATERIAL Filed July 19, 1962 I 2 Sheets-Sheet 1 fiilswucn PslravuiassnUnited States Patent APPARATUS FOR CONTINUGUS EXTRUSIGN 0F COMPOSITEBODIES 0F PLASTIC MATERIAL Friedrich Reifenhiiuser, Troisdorf-Cologne,Germany, as-

signor to Reitenhiiuser K.G., Troisdorf-Cologne, Germany iled July 19,1962, Ser. No. 211,031

4 Claims. ((11. 18-13) The present invention is concerned with animprovement of an apparatus with a nozzle arranged concentrically in anextrusion head for the continuous extrusion of endless formed bodies, inparticular of plate-like building elements which are comprised of anoise and heat dampening and insulating core of extrudable foamedfilling material and a surrounding shell or jacket of thermoplasticsynthetic material. There is here presented an improvement andelaboration of the proposals of Friedrich Reifenhauser US. patentapplication Ser. No. 56,087 filed September 8, 1960 and now abandoned.

In accordance with prior practice represented by the above named patentapplication, the nozzle or nozzles for the core-forming light fillingmaterial, centrally disposed in the extrusion head of an extrusionpress, are enclosed by a slit nozzle advantageously of fiat prismaticcross section for the production of the shell.

From such nozzles the materials for the shell and the core aredischarged simultaneously; and in addition immediately behind thesenozzles is disposed a somewhat box-like calibrating apparatus of formknown to the art, in which the still plastically formable hollow body,issuing from the extrusion head and intended as a shell, is caused tolie against or conform to the inner wall of the sizing device throughthe action of vacuum applied to the shell exterior surface. Also in aknown arrangement, behind the sizing apparatus, beyond a cooling device,there is located a product withdrawal mechanism and at times a cut offapparatus as well.

It is now found that this proposal can be elaborated and improved bydisposing one, two or more screw presses for the production of theexternal shell laterally of the common extrusion head at about rightangles to the extrusion direction or in diametrically opposed relationto one another, and discharging into the extrusion canal leading to thecommon extrusion nozzle for the shell; and in this case the extrusionhead is provided with a central aperture, on one side standing in directconnection with the hollow space of the extruded shell and on the otherexpanding outwardly into a conically shaped opening, into which may beintroduced a coreproducing extrusion nozzle.

This arrangement has the advantage that the central part of theinjection head, in communication with the hollow space of the extrudedhollow body, is open and accessible from the exterior.

Accordingly, in this central opening there may be selectively disposedthe extrusion head of an extrusion machine or even a swiveling extrusionhead which can also be removed during operations. The introduction ofmaterial from opposite sides further renders it possible to supplyrelatively large quantities of these materials to the extrusion head andthereby either to accelerate production or to produce flat bodies ofconsiderable wall thickness, as may be necessary for certain intendedapplications.

Other objects and advantages will appear from the following descriptionand the drawings, representing examples of an embodiment of theinvention, wherein:

FIG. 1 in schematic representation is a longitudinal section through theapparatus with the extrusion nozzle 3,189,941 Patented June 22, 1965 ofa screw press extrusion machine centrally located therein;

FIG. 2 is a similar longitudinal section, showing, however, a swivelednozzle introduced in the central open- 111g;

FIG. 3 is a plan view of the apparatus as shown in FIG. 1;

FIG. 4 is a longitudinal section through the sizing and cooling devicewith product withdrawal mechanism; and

FIG. 5 is a cross section through the extrusion nozzle taken asindicated by the line VV in FIG. 3.

The apparatus (see FIGS. 1, 3 and 5) :is comprised of the oppositelydisposed screw presses l which are attached to the common extrusion head2 having an annular supply channel 3 through which the shell-formingplastic material is led to the extrusion nozzle 4 of closed slit-likeform, from which issues the extruded hollow body 5.

In this common extrusion head there is provided a central hollow freespace 6 into which the extrusion nozzle 7 of a screw press 8 can beintroduced, for injecting the desired core or filler material 5C intothe hollow space of the simultaneously extruded hollow body.

The hollow body is further formed through the sizing and cooling section9 standing under a vacuum, and after cooling and solidification thereinis continually drawn off through a withdrawal mechanism including therolls 10 (see also FIG. 4). The rolls 10 preferably are driven by any ofthe many known apt means (not shown) at a speed suitable, relative tothe rate at which material is supplied to and extruded by the apparatus,to provide a desired wall thickness in the shell portion 5 andcompactness in the core 5C.

In the apparatus section 9, the tube 11, aligned with the nozzle 4 ofand abutting the head body 2, has an interior wall surface correspondingto the external crosssectional shape desired in the shell 5, and isprovided with a water or coolant jacket 12 thereby to form coolingmeans; and at 11a has a portion of its length provided with a largenumber of perforations about its entire circumference, through which avacuum is applied to the exterior of shell 5 as it is being produced,through a surrounding vacuum collar or jacket 13, serving to draw theyet plastically deformable shell material into conformity with the innersurface of tube 11 and thereby forming product sizing or calibratingmeans.

In the example of FIG. 2, into the hollow space 6 of the extrusion head2 there extends a swiveling extrusion tube 11 upon removal of which theinterior space of the extruded hollow body 5 is accessible from theexterior of the apparatus.

I claim:

1. For the continuous extrusion of shaped bodies, par ticularlyplate-like construction elements having an extruded foamed sound andheat insulating core and a surrounding thermoplastic synthetic plasticshell, apparatus comprising:

an extrusion head;

a separate core material extrusion nozzle means disposed in saidextrusion head;

slit nozzle means in the head concentrically surrounding the first meansand having a fiat prismatic cross sictlion for the extrusion of a hollowbody as the said s e1;

said apparatus adapted for simultaneous discharge of the shell and corematerials;

a sizing device disposed immediately beyond said nozzle means adapted toapply a vacuum on the external surface of a hollow body issuing from theextrusion 'head while yet plastically deformable to bring the same intoconformity with a size calibrating inner Wall of the sizing device;

a screw press for supplying to the slit nozzle means 3 4 material forthe hollow body and disposed laterally References Cited by the Examinerof the extrusion head; said extrusion head having therethrough a centralUNITED STATES PATENTS opening in communication on one side with the in-1933212 10/33 Gora 18 12 terior space of the hollow body extruded fromthe 5 1,934,647 11/33 State et a1 18-12 slit nozzle means and on theother side conically 21443116 5/41 osiermann expanding to the exteriorof the head; 33319 27 12/43 Relchel 1814 said core producing extrusionnozzle means being struc- 9/48 Stuart 18 '12 turally independent of saidslit nozzle means and 2569373 9/51 Fay 13 13 movable into and out of acore-filling operative dis- 10 2587553 8/54 Colomba 18 13 position insaid central opening. 2719778 9/55 18 13 2. An apparatus improvement asdescribed in claim 2764739 9/56 Weiss 18 59 1 wherein the extrusionnozzle means for the foarnable 2789315 4/57 Plstor et a1 18-8 corematerial is swivelly mounted for introduction to and 280'7833 10/57sqhanz 18-42 withdrawal from said head without disturbing said slit 153099859 8/63 Ellersen 18 12 nozzle means. FOREIGN PATENTS 3. Anapparatus improvement as described in claim 1 207 3021 1/60 Austriaincluding a plurality of said screw presses discharging 8%:391 10/61Great l'gritain irliomaegggimon extrusion channel supplying said slit1102- 503,415 12 /5 4 Italy.

4. An apparatus as described in claim 3 including at WILLIAM STEPHENSONPfimary Examiner least two of said presses disposed on said head in 0p-ROBERT F. WHITE, MECHAEL V. BRINDISI,

posed relation to each other. Examiners.

1. FOR THE CONTINUOUS EXTRUSION OF SHAPED BODIES, PARTICULARLYPLATE-LIKE CONSTRUCTION ELEMENTS HAVING AN EXTRUDED FOAMED SOUND ANDHEAT INSULATING CORE AND A SURROUNDING THERMOPLASTIC SYNTHETIC PLATICSHELL, APPARATUS COMPRISING: AN EXTRUCION HEAD; A SEPARATE CORE MATERIALEXTRUSION NOZZLE MEANS DISPOSED IN SAID EXTRUSION HEAD; SLIT NOZZLEMEANS IN THE HEAD CONCENTRICALLY SURROUNDING THE FIRST MEANS AND HAVINGA FLAT PRISMATIC CROSS SECTION FOR THE EXTRUSION OF A HOLLOW BODY AS THESAID SHELL; SAID APPARATUS ADAPTED FOR SIMULTANEOUS DISCHARGE OF THESHELL AND CORE MATERIALS; A SIZING DEVICE DISPOSED IMMEDIATELY BEYONDSAID NOZZLE MEANS ADAPTED TO APPLY A VACUUM ON THE EXTERNAL SURFACE OF AHOLLOW BODY ISSUING FROM THE EXTRUSION